Some embodiments relate to a fiber connection assembly comprising a first and a second coupling member, to a coupling member for use in such an assembly and to a fiber termination unit for connecting an optical fiber to a network termination unit.
In a fiber based communication network that connects end-user premises, like fiber-to-the-home (FttH), the user premises is connected to the access network based on optical fibers. Optical fibers allow end-customers/consumers to make use of broadband services, provided by a service provider. There are different levels in the topology of the access network. The lowest level consists of the passive infrastructure and contains the cables and physical connections required to connect the end-customers to the network. Higher levels allow for the data transport using the passive infrastructure, using e.g. the Ethernet-protocol or the GPON-protocol. This allows service providers to deliver the service(s) to the end-customers (i.e. Internet, telephony, cable TV, IP-TV, and in the future services like health-care).
The passive infrastructure contains the fiber cables (and possible other components required, like splitters, filters, (de)multiplexers), which are mainly deployed in the ground or on poles. It realizes the physical connection from the so-called Central Office (CO) to the end-customer. Part of the passive infrastructure are the properly installed fibers at the end-customer premises. These fibers are typically mounted in a so-called Fiber Termination Unit (FTU). The remainder of this document will focus on the FTU and connection mechanism with the Network Termination Unit (NTU), explaining the state-of-the-art today and introduce a new concept.
Because optical fiber is delicate and because the connection of one optical fiber to another requires considerable accuracy, care must be taken when installing fiber in a user premises or home. Therefore the installation of the fiber is often performed by skilled professionals. It requires the right skills, know-how and equipment in order to get the job done.
A protective cable containing one or more optical fibers enters the home through a wall. A FTU can also be installed outside, which is common practice in the US. The cable is brought to a location convenient for installing the FTU. The FTU is often mounted on a wall. As stated above, the FTU serves as the end-point for the fiber cable coming from the outside. The FTU typically contains a means for strain relief for the protective cable, a means for storing or rolling up the fiber(s), and a connection of the optical fiber(s) in the cable to one or more optical connectors or connectorized fiber(s) (so-called pigtail(s)). This connection is often realized by using fusion splicing—melting the two glass fibers to each other. This is executed with a very high accuracy to minimize the optical loss. It should be noted that the most commonly used fiber in FttH, standard single mode fiber (e.g. G652, G657, etc.), contains the light in the inner core having a diameter of on the order of 10 micrometer. After the installation of the FTU, an optical connection point has been created, often as an optical connector or optical adapter.
When the end-customer has received a FTU in his premises and wants to start using services delivered via his fiber connection, the fiber connection needs to be activated. In the CO this means that the fiber is connected to a so-called access switch or Optical Line Terminal (OLT), equipped with an optical interface. At the customer side, a product is to be attached to the fiber that receives the optical signals and converts these in electronic signals and vice versa. This product is called a Network Termination Unit (NTU), or an Optical Network Terminator (ONT), or an Optical Network Unit (ONU), since it terminates the optical network and is the actual demarcation point between the transport network and the services that the end-user consumes.